Agkistrodon bilineatus lemosespinali
Smith & Chiszar (2001) described a new subspecies of Agkistrodon bilineatus on the basis is a single specimen from near Palma Sola, Veracruz, Mexico: A. b. lemosespinali. The new subspecies differs from the other currently recognised ssp. of A. bilineatus in aspects of head scalation (fragmented prefrontals), in having a shorter tail and a longer snout, and aspects of pattern. The distributional record for the holotype fills a gap in the distribution of the A. bilineatus complex along the eastern coast of Mexico: A. taylori is restricted to northeastern Mexico, whereas A. b. russeolus is found only in the northern Yucatan Peninsula.
Bothrocophias hyoprora Bothrocophias microphthalmus
Gutberlet & Campbell (2001) described a new genus of pitviper, Bothrocophias. This includes several species of pitviper of problematic generic affinities: hyoprora was generally regarded as part of Porthidium (e.g., Campbell & Lamar, 1989), whereas the species microphthalmus and campbelli (often under the incorrect name pulcher - see 1999 publications below) were usually regarded as part of Bothrops. In addition, Gutberlet and Campbell noted that specimens from the lowlands of southwestern Colombia previously assigned to B. campbelli belong to a different species than specimens from higher elevations on the western slopes of the Ecuadorian Andes. The Colombian lowland form was therefore described as a new species, Bothrocophias myersi, whereas the name B. campbelli was restricted to the highland species from the Ecuadorian Andes.
Bothrops leucurus and B. pradoi
Puorto et al. (2001) analysed mitochondrial DNA and morphological variation in populations of the Bothrops atrox complex along the Atlantic coast of Brazil. Conventionally, these were regarded as two separate species, Bothrops leucurus and B. pradoi. In the present study, Puorto et al. found minimal mtDNA sequence divergence and gradual, clinal variation in morphology. Characters previously used to distinguish B. leucurus and B. pradoi were found to be associated with sex or ontogeny rather than phylogeny. Puorto et al. concluded that B. leucurus and B. pradoi are part of one single species, B. leucurus.
Ferrarezzi & Freire (2001) described the new species Bothrops muriciensis from the State of Alagoas, northeastern Brazil. The new species is part of the group of large, robust, terrestrial species with intact lacunolabial scales that also includes B. jararacussu, B. brazili, B. pirajai and B. sanctaecrucis. It differs from other species in this group in having a very low number of ventral scales and dorsal blotches, as well as other pattern features. The new species is known from only three specimens, the largest of which measured 884 mm in total length. All known specimens have been collected from a small part of the forest "Mata de Murici". This forest represents the largest remnant of the northern sector of the Brazilian Atlantic forest, one of the world's biodiversity hotspots, and yet also one of the most threatened ecosystems in S. America. The new species must be regarded as critically endangered due to its small remaining distribution and the lack of adequate protection afforded to its range.
Crotalus viridis - Western rattlesnake
Crotalus viridis Crotalus oreganus
Ashton & de Queiroz (2001) analysed mtDNA variation across the range of Crotalus viridis. Their results were broadly similar to those obtained by Pook et al. (2000) (see Crotalinae 2000 page). The authors identified two main clades, east and west of the Rocky Mountains, which they regard as two distinct species, Crotalus viridis (including the conventional subspecies viridis and nuntius) and Crotalus oreganus (including all other tradtional subspecies of C. viridis). The authors retain the traditional subspecies, but emphasise the need for more work on the systematics of C. oreganus.
Trimeresurus albolabris - White-lipped pitviper
Giannasi et al. (2001) used AFLPs to test systematic relationships previously inferred from mitochondrial DNA sequence evidence (Malhotra & Thorpe, 1997, 2000). In particular, mtDNA analysis had revealed extensive differentiation between T. albolabris from the Asian mainland and West Java on one hand, and populations from East Java and the Lesser Sunda Islandson the other. A specimen of the isolated population from Nepal was also found to be highly distinct. The same pattern was found in the present AFLP study. In view of the congruent results of mitochondrial DNA sequences and the AFLP data, Giannasi et al. regard the Lesser Sunda and East Java populations as a separate species, Trimeresurus insularis, and the Nepalese population is equally regarded as a full species, Trimeresurus septentrionalis.
Trimeresurus vogeli - adult male
David et al. (2001) describe Trimeresurus vogeli from southeastern Thailand. The new species is related to T. stejnegeri, with which it was formerly confused. According to David et al. (2001), it can be distinguished from other species of the complex in lacking red in the postocular stripe, in a series of light vertebral spots in males, a largely green tail (only the last 20-25% being mottled with reddish-brown), and in normally lacking any red in the ventrolateral stripe. The new species is large (to 130 cm), and has so far been found in the Thai Provinces of Nakhon Ratchasima, Chanthaburi, Prachin Buri, Trat and Krabi. The authors emphasise that more work on the T. stejnegeri complex is required.